The ability to run DO through your PreApp account is dependent on your Integration settings.
Click the Gear Icon on your dashboard, select System Settings and click PreApp Integrations on the Nav Menu to the left.
Use the gears to the far right of the Fannie Mae option to open the FannieMae Settings Page.
Fill out the first and second sections.
If your credit agency is not an option on the drop down, send a detailed message to support@preapp1003.com.